Two-dimensional ZIF-L derived dual Fe/FeNx sites for synergistic efficient oxygen reduction in alkaline and acid media

Jun-Fei Gu; Jichao Wang; Caixia Wang; Jin Li; Cheng Chen; Ni Zhang; Xiang-Ya Xu; Somboon Chaemchuen

doi:10.1016/j.jcis.2025.01.089

Two-dimensional ZIF-L derived dual Fe/FeN_x sites for synergistic efficient oxygen reduction in alkaline and acid media

J Colloid Interface Sci. 2025 Jan 13;684(Pt 2):159-169. doi: 10.1016/j.jcis.2025.01.089. Online ahead of print.

Authors

Jun-Fei Gu¹, Jichao Wang², Caixia Wang³, Jin Li⁴, Cheng Chen⁵, Ni Zhang⁶, Xiang-Ya Xu⁷, Somboon Chaemchuen⁸

Affiliations

¹ State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070 China.
² School of Marine Science and Technology, Northwestern Polytechnical University, 127 Youyi Road, Xian 710000 China; Ningbo Institute of NPU, 218 Qingyi Road, Ningbo 315100 China.
³ School of Civil Engineering and Architecture, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070 China. Electronic address: [email protected].
⁴ Department of Gastroenterology, The Eighth Affliated Hospital, Sun Yat-sen University, Shenzhen 518033 China.
⁵ State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070 China; Sanya Science and Education Innovation Park of Wuhan University of Technology, Sanya 572000 China. Electronic address: [email protected].
⁶ Hubei University of Technology Engineering and Technology College, Wuhan 430068 China.
⁷ Department of Catalytic Sciences, SINOPEC (Beijing) Research Institute of Chemical Industry Co., Ltd, No. 14 Beisanhuan Donglu, Chao Yang District, Beijing 100013 China.
⁸ State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070 China; Department of Chemical Engineering, Faculty of Engineering, Mahidol University, Nakhon Pathom 73170 Thailand. Electronic address: [email protected].

PMID: 39826503
DOI: 10.1016/j.jcis.2025.01.089

Abstract

Fe-N-C catalysts have emerged as the most promising alternatives to commercial Pt/C catalysts for oxygen reduction reaction (ORR) due to their cost-effectiveness and favorable activity. Herein, a dual-site Fe/FeN_x-NC catalyst was synthesized via a green, in situ doping strategy using two-dimensional Fe-doped ZIF-L as a nitrogen-rich precursor. The catalyst integrated Fe nanoparticles (NPs) and FeN_x sites anchored on carbon nanotubes, intertwined with nitrogen-doped porous carbon nanosheets, achieving a high active site density and graphitisation. Electrochemical tests revealed that the optimized Fe/FeN_x-NC-1 exhibited significant ORR activity, with a half-wave potential of 0.92 V and 0.80 V for alkaline and acidic medium, respectively. Zn-air batteries employing Fe/FeN_x-NC-1 delivered a peak power density of 168 mW·cm^-2 and a specific capacity of 790 mAh·g^-1, outperforming those of Pt-based catalysts. Density functional theory calculations demonstrated a reduced free energy barrier for the rate-determining step (0.48 eV) compared to single-site Fe-N₄ models (0.79 eV). The synergy between Fe NPs and FeN_x optimized ORR intermediate adsorption and facilitated charge/mass transfer. This study offers valuable insights for the development of advanced energy conversion systems.

Keywords: Carbon nanotubes; Iron nanoparticles; Iron single atoms; Oxygen reduction reaction.